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Existence and positivity of the limit in processes with a branching structure

Published online by Cambridge University Press:  14 July 2016

M. P. Quine*
Affiliation:
University of Sydney
W. Szczotka*
Affiliation:
University of Wrocław
*
Postal address: School of Mathematics and Statistics, University of Sydney, NSW 2006, Australia.
∗∗Postal address: Mathematical Institute, University of Wrocław, Pl. Grunwaldski 2/4, 50–384 Wrocław, Poland.

Abstract

We define a stochastic process {Xn} based on partial sums of a sequence of integer-valued random variables (K0,K1,…). The process can be represented as an urn model, which is a natural generalization of a gambling model used in the first published exposition of the criticality theorem of the classical branching process. A special case of the process is also of interest in the context of a self-annihilating branching process. Our main result is that when (K1,K2,…) are independent and identically distributed, with mean a ∊ (1,∞), there exist constants {cn} with cn+1/cna as n → ∞ such that Xn/cn converges almost surely to a finite random variable which is positive on the event {Xn ↛ 0}. The result is extended to the case of exchangeable summands.

Type
Research Papers
Copyright
Copyright © Applied Probability Trust 1999 

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Footnotes

W. S. partly supported by an Australian Research Council Institutional Grant and by grant KBN, no. 2 PO3A 056 09.

References

Athreya, K. B., and Ney, P. E. (1972). Branching Processes. Springer, Berlin.Google Scholar
Bru, B., Jongmans, F., and Seneta, E. (1992). Bienaymé, I. J.: Family information and proof of the criticality theorem. Internat. Statist. Rev. 60, 177183.Google Scholar
Chow, Y. S., and Teicher, H. (1978). Probability Theory. Springer, New York.Google Scholar
Cournot, A. A. (1847). De l'origine et des limites de la correspondance entre l'algèbre et la géometrie. Hachette, Paris, Section 36. Reprinted (1989) Vrin, Paris.Google Scholar
Erickson, K. B. (1973). Self annihilating branching processes. Ann. Prob. 1, 926946.CrossRefGoogle Scholar
Grey, D. R. (1980). A new look at convergence of branching processes. Ann. Prob. 8, 377380.Google Scholar
Grey, D. R. (1996). Personal communication.Google Scholar
Quine, M. P., and Szczotka, W. (1994). Generalizations of the Bienaymé-Galton–Watson branching process via its representation as an embedded random walk. Ann. Appl. Prob. 4, 12061222.Google Scholar
Quine, M. P., and Szczotka, W. (1998). Asymptotic normality of processes with a branching structure. Comm. Statist. Stoch. Models 14, 833848.Google Scholar